First of all, in the practical application of stamping, considering the weakening of the strength of the opening on the head, the sealing of the head and the barrel is convenient. Secondly, we use the ellipsoid as the head of the container on the chemical equipment, Lowering the height of the device will facilitate stamping. The maximum hoop tensile stress at the top of the ellipsoid is exactly equal to the maximum hoop compressive stress at the periphery of the ellipsoid (the equatorial circle). At this time, the maximum film stress value in the head is also equal to the hoop stress in the same diameter and the same wall thickness. The maximum stress in the elliptical head will also increase, and the maximum value (absolute value) of the hoop stress will move from the top of the ellipsoid to the periphery of the ellipsoid. If an elliptical circular hole is opened in the cylinder, the short axis should be parallel to the axis of the cylinder.

Let's take a look at the similarities and differences between the three stress analysis methods of the head. Firstly, the analytical method is convenient to calculate the stress of some rotating thin shells, but it has some limitations. The analytical method is more complicated for the calculation of some irregularly shaped or a certain thickness of the container. Secondly, the experimental electrical measurement method of the head is widely used. In theory, the stress value measured by the experimental method is closest to the actual value, but the error of the experimental method produces more sources, and the error is sometimes larger. Thirdly, the analysis of stress by finite element method is a relatively accurate method. The error size mainly depends on whether the measurement of the size of the container is accurate, and the scope of its use is also wide.